text:
Why can’t level D simulators produce a G-force effect?
From what I know so far, simulators can’t simulate this feeling, I’ve heard some say it will never be possible. Is that true? There’s really no way of producing this in a simulation?

Not without a centrifuge. They can make very short/small G forces, but not sustained. Mostly they just move 1-G vector around.

Yes, it'd true.  Basic physics, really.

Well, at the moment there are only two known ways to create G's, 1) accelerate you, 2) create or move a large mass close to you. The first is approach isn't much cheaper than a real flight, the second way is... considerably more difficult than a real flight.

There is a way.  Mount the sim inside an airplane that is perfoming the same maneuvers that you wish to simulate.

The short answer is: because the room containing the simulator has a ceiling, floor, and walls, through which it is not desired that the simulator travel.  Since the integral of acceleration is non-zero, acceleration implies velocity which implies distance travelled.  For rooms of a reasonable size, this impiles that only very limited accelerations may be realistically simulated without bursting through the physical walls of the room containing the simulator.

They can produce sustained G-forces, by tilting the sim without the occupants noticing. Of course, this tilting of the 1G gravity vector is limited to practical angles of about 45°, producing 0.7G of simulated sustained horizontal acceleration.
Vertical sustained acceleration is a different matter altogether: the 1G is always already there and can only be reduced by tilting the sim, while in manoeuvres with increased load factor we're looking to increase beyond 1G.
Fortunately the inner ear sensors can be tricked to an extent: they are very good at detecting acceleration onsets but get flooded by sustained acceleration inputs. Our brain seems to rely on the inner ear for detecting the first onset of acceleration, then on our peripheral vision to read the motion velocity. So if we heave the sim rapidly and show the movement on the visual, we cannot detect very readily if we're not pressed down by g-forces anymore after some time.
Image source
Level D simulators are for civil aviation training, which teaches how to limit load factor. Military sims are a different kettle of fish, as mentioned in this answer. G-seats like depicted above provide cues to our body skin sensors, as do G-suits.

Centrifuges can of course produce sustained g-forces, and they do exist, used by the military to train sustained g flying and by medical facilities to check how long a person can remain conscious. A combination of a centrifuge with a civil 6-DoF system is not really possible for realistic acceleration simulation.

When one side of the seat deforms as shown in the illustration, wouldn't it be simulating the sensations of sideslip or skid, not the sensations of a coordinated turn?

@quietflyer yes correct, a co-ordinated turn would be simulated by increased seat cushion pressure and lowering of the complete seat, with associated shoulder belt slackening.

The only G forces the simulator can simulate are sustained lateral forces, which you feel when it tilts, and very limited short vertical and lateral accelerations.
A tilt aft feels like acceleration/climbing, a tilt forward feels like deceleration/descending, and tilts to the side feel like you are skidding.
The only vertical accelerations the sim can reproduce are short bump sensations and other brief vertical motions made possible by the ability to of the hydraulic jacks to jerk the machine up or down briefly a few feet.  The sim is also good at doing short lateral jerking motions that you would feel when touching down in a crosswind with a bit of crab in.
The sim cannot reproduce sustained turning G force sensations and it can't reproduce the long term turning effects on your inner ear because it can't rotate in a sustained way.
The most realistic effects are the acceleration/braking effects, especially takeoff and landing sensations, and short term vertical and lateral effects meant to simulate bumps and things like flap deployment, and pavement seams, side movements while rolling on the ground, that sort of thing.  The most unrealistic effect is the round out and flare to land, because the sim can't reproduce the mild G increase when you pitch up and you get a weird kind of floating sensation in your head when you do it (at least I did).
Because the force simulations are limited, once you've done a fair amount of training in them, you start to become more aware of the odd disconnects between the view on the screen and the seat of the pants sensations, and then you start to become more aware of the faint sound of the hydraulics running outside, which spoils the effect even more, and you're less apt to get mentally lost in it and forget you're not in the real a/c, except when you're put into extreme scenarios that are close to overwhelming your brain.
You could simulate sustained G forces by having the sim gimbal mounted in a massive centerfuge but it's not worth the expense to get that extra realism (they are expensive enough as it is and no airline would pay for it).

The short answer is: because the room containing the simulator has a ceiling, floor, and walls, through which it is desired that the simulator not travel. Since the integral of acceleration is non-zero, acceleration implies velocity which implies distance travelled. For rooms of a reasonable size, this implies that only very limited accelerations may be realistically simulated without bursting through the physical walls of the room containing the simulator.

The ACME Worldwide Enterprises motion cueing simulator seat CAN produce a G-force affect. They can be used with military or commercial simulators and utilize technologies placed inside a replica seat's back pan, seat pan, shoulder and lap belt harnesses to simulate g-onset and up to 1.8G sustained g-cues. The signal to the seat comes from the aircraft flight (acceleration) model so the signal to the visuals (and platform motion if used) is the same signal to the motion-cueing seat.

I read "ACME" and immediately think Wily E. Coyote. This answer has a spammy feel to it - seems like it was copy/pasted straight out of some marketing material. Do you have any affiliation with the company? You may want to [edit] your post to indicate one way or the other.

Why 1.8?  What is so special about 1.8?  Why not 1.9?  Please explain in more detail.

I dunno, this think looks like something I need in my SIM setup.  https://player.vimeo.com/video/256155117


text:
What standard of English are Air Traffic Controllers held to?
While I'm sure it varies by territory, and that airports around more cosmopolitan areas have controllers better versed in English, I was wondering how well controllers have to know English. I imagine that there are places where all of the English they know is aviation-related. I can imagine that there are situations in which lack of knowledge of the language outside of memorized aviation vocabulary could be harmful, and situations in which a translator might be needed. How well versed in English are ATCs?

hello there, I see three questions: one in the title, another two in the question body. At its current status, I'd say it is too broad for the site. If you can narrow the scope, it'd be great.

Waiting to reopen. Sure it is relevant here.

Possible duplicate of Which specific version of English are international pilots and ATC required/recommended to learn?

@mins Similar, but that question seemed to focus on the "flavor" of English used, whereas I'm trying to figure out the proficiency required (to determine if it would affect operational ability)

@kevin Thank you for the notice. Reworded accordingly.

The other question covers this topic and also provides the ICAO proficiency criteria.

Related, at least for the part about the interpreters (not translators!)

You might want to have a look into ICAO Language Proficiency Rating Scale. The article suggests that

In 2003, ICAO set a deadline of March 2008 for English language
  proficiency at Level 4 and above for all pilots flying international
  routes and air traffic controllers serving international airports and
  routes.

Original text is not in bold.
In the same link, you can also find the description of each rating scale, as described in the Manual on the Implementation of ICAO Language Proficiency Requirements Doc 9835 AN/453, quoted here for convenience:

As of translators on call, I've never heard of such a practice and if I judge from the Level 4 being the minimum, that wouldn't be necessary.

Air traffic controllers need an ICAO English proficiency level 4 or above.
You can see what the different levels require here:

Source: http://www.skybrary.aero/index.php/English_Language_Proficiency_Requirements
The English proficiency is tested when the ATC certificate is first issued, and then repeatedly after a number of years, depending on the level (the lower level you get, the more often you need to be tested).

I believe (but feel free to correct me if I'm wrong) that if you get a Level 6, no further testing is required in that language.

@michaelkjörling It used to be like that, but that has been changed. Now level 6 is valid for 9 years IIRC

I actually asked a local examiner about that. His answer was that it varies between countries even within the EU. For pilots in Sweden, level 6 is valid indefinitely.

@michaelkjörling Fair enough, I just know I have to renew mine :D

For pilots, it's valid indefinitely, for ATCOs, a level 6 ICAO English is only valid for 9 years. At least in Slovakia.

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text:
How common is engine failure?
What are the failure rates for piston, turbine, and jet engines? (If more subdivisions of "engine" are necessary to make the data useful, please point them out).

Related: Does one have to practice engine failures in flight training?. Statistics will be hard to come by for anything other than damage events. Typically the NTSB takes a "no harm, no foul" approach to most engine failures that don't result in major damage or injuries, and does not make a report on them.

@Ron Beyer Would jet engine failures in commercial aircraft be reported?

Probably not because it's usually a non-event, unless it resulted in a multi-engine failure or crash.

At least a partial dupe of this question but I wont vote to close as there are other questions here.

This question is a bit to broad after a re-read, as it stands as its asking essentially 3 questions but could easily be modified.  Are you looking for individual rates, comparison by year, by aircraft size. Keep in mind piston planes have been flying for over 100 years and jest for half that. A lot of manufacturing tech changed in that time. Are you trying to get to a more specific data point?

http://avherald.com/h?search_term=engine+shut+down&opt=0&dosearch=1&search.x=0&search.y=0

Engine failures absolutely are reported to the authorities, however it does not always become public information.

@Dave I don't have time to jest for 50 years, sorry. *baddum-tsh*

Engine failure is not that common. For a gas turbine engine, a press release by GE gives some data as a reference point. In 1995 they quoted various engines as having a dispatch rate of between 99.99% and 99.89%. That is only 0.01 to 0.11 % of flights could not depart due to an engine issue. However, that doesn't identify in flight failures, best captured by the inflight shut down (IFSD) rate. Data on this is difficult to get for specific engines, as the OEMs consider it competitive information, so the best guide is probably as mentioned the ETOPS rating. The ETOPs fleet is reported as achieving a shut down rate of less than 0.01 per 1000 engine hours. Another way of defining reliability is the (repair) shop visit rate (SVR). Figures given for this (by GE in the same link as above) were between 0.085 and 0.231 visits per 1000 flight hours. However, this covers both scheduled and unscheduled maintenance (i.e. failures), so perhaps doesn't identify what you want.
For piston engines, the answer to this  question probably has some useful data. In addition, Continental claimed in 2014 that they had an IFSD rate of 0.0061 per 1000 flight hours, which they claim is the most reliable piston engine in general aviation. This compares with "less than" 0.01 for gas turbines, so, it seems very similar.
It maybe possible to find a better value for the IFSD rate for gas turbines. Given the rate is so low, it really needs to be quoted to more than 2 decimal places, or given per 100,000 flight hours. Ultimately, I would expect the IFSD rate for gas turbines to be lower than for piston engines, due to the huge economic incentive gas turbine manufacturers and the commercial airline industry has increasing reliability for turbofan engines, that does not exist to the same extent, for general aviation piston engines.

The statistics above are very misleading as to failure rates of turbine engines. Keep in mind ETOPS engine fail rates are based on shutdowns. Most of the time, the engine does not fail but is shut down as a precaution because the aircraft has sensed some deviation from normal engine parameters. Often this turns out to be a fault in the monitoring system as opposed to an actual failure.
I do not have the statistics at hand but I can say with some certainty that the failure rates of piston engines are tens of times higher and the fatality rates are much higher as well.
I just retired from airline flying with close to 30,000 hours. 26,000 of those were in jets and jetprops and I NEVER had an engine failure or a precautionary shutdown. In the 4,000 hours of piston time, I have had four engine failures, all in twins. Two were complete and two were partial. I have owned 4 different private planes. Two piston singles, a piston twin and now fly a single engine turbine powered aircraft.

how can you say that "The statistics above are very misleading" if you "do not have the statistics at hand"? Can you please edit your answer and link the statistics you mean?

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text:
Flying N-registered Aircraft in the EU (as an EU resident)
Until recently, I believed what the old, wise men of my local flying club had been telling me for years:

You can fly N-registered aircraft in Europe... as long as you have an FAA license.

I recently tried to research the relevant section of EU law, just to be sure. As it turns out, matters are (much?) more complicated. So far, I was able to determine:

Flying an N-reg. Acft. in...
while being a resident of...
license requirement
comment

EU member state
EU member state
FAA + EASA (since 2021)
claimed by [1] and [2], but why?

EU member state
non-EU member state
FAA
claimed by [1] and [2], but why?

US
US
FAA
Title 14

US
non-US
FAA
Title 14

(I am referring to EASA Part-FCL member state pilot's licenses as "EASA licenses" in the following)
What I understand:
The 2020 (in force 2021) BASA bilateral treaty between the EU and the US makes it easier to obtain a "standalone" EASA license based on an FAA license (and vice-versa). This is sometimes known as the TIP-L process (from "Technical Implementation Procedures - Licensing").
Various sources, including regional AOPA offices [1] and the European Commission [2] state that this regulation now compels EU residents to have both an FAA license and an EASA license to fly N-registered aircraft in the EU. From the regulation alone, I do not see why this is the case.
Also, Article 33 "Recognition of certificates and licenses" of the Chicago convention states:

Certificates of airworthiness and certificates of competency and licenses issued or rendered valid by the contracting State in which the aircraft is registered, shall be recognized as valid by the other contracting States, provided that the requirements under which such certificates or licenses were issued or rendered valid are equal to or above the minimum standards which may be established from time to time pursuant to this Convention.

My questions are therefore:

Where, in EU law, does it state that an EU resident must hold a valid FAA license and a valid EASA license to fly an N-registered airplane?
Where, in EU law, does it state that a non-EU resident must hold "only" a valid FAA license to fly an N-registered airplane?
(Is this simply Article 33 of the Chicago convention? If so, I am guessing that this is regulated at the national level, since individual countries are signatories to the Convention, not the EU?)
Where, in EU law, are those countries listed to which Article 33 of the Chicago Convention applies (ie. those countries whose licenses are recognized)?
(Is this related to Commission Delegated Regulation (EU) 2020/723, which now amends the EASA Easy Access Rules for Aircrew?)

[1] AOPA Luxembour blog post
[2] Archived summary by the European Commission

After a significant amount of further research, I finally found a post by policy expert Jyrki Paajanen of DG MOVE (EU Directorate for Transport) in the EASA Community Forum:

The EASA Basic Regulation Section I, Article 2(1)(b)(ii) determines that the operation of aircraft is subject to the Basic Regulation, if they are “registered in a third country and operated by an aircraft operator established, residing or with a principal place of business in the territory to which the Treaties apply”. This means also holding a Part-FCL licence to fly a third-country registered aircraft.

EASA Basic Regulation Section II, Article 21 further states:

Pilots shall be required to hold a pilot licence and a pilot medical certificate appropriate to the operation to be performed (...)

Which of course implies that an EASA member-state license is required.
This explains that EASA Basic Regulation always required aircraft operators (=pilots) with EU-residence to hold a valid EASA member-state license. Ok, but where did it previously say that this requirement could be derogated by member states?
To find this out, further research was required. Fortunately, I found a notice published by the Irish Aviation Authority:

Since the introduction of Commission Regulation (EU) No 1178/2011 of 3 November 2011 as regards technical requirements
and administrative procedures related to civil aviation aircrew, Ireland has availed of available derogations relating to pilots
holding a licence and associated medical certificate issued by a third country involved in the non-commercial operation of
aircraft as specified in Article 2(1)(b), points (i) or (ii), of Regulation (EU) 2018/1139.
The last available derogation, Article 12 – 4 of Regulation (EU) No. 1178/2011 as amended by article 1(1) of Regulation (EU)
No. 2020/2193 ceases on 20 June 2022. The EU has not indicated that further derogations will be forthcoming.

Does this not run counter to the Chicago Convention? To the legal layperson, it would seem so. The AOPA Luxembourg blog post seems to suggest that the EU is still technically in breach of the Convention, although now to a "lesser degree" :

European countries and EASA [note: prior to signing the BASA bilateral treaty between the EU and the US] were not abiding to the terms they had accepted on licensing when becoming members of ICAO. (USA would accept private licenses coming from other ICAO member countries, but European countries did not reciprocate), therefore these countries were in breach of the international treaties they had signed.

And indeed, in the US, it seems to be enough to have a license of the state in which the aircraft is registered, as per 14 CFR 61.3(b), irregardless of the seat of residence of the pilot (see also this answer on the Aviation StackExchange).
For completeness, I am including the relevant sections of two AOPA blog posts which mentioned the new requirement to have both an EASA license and an FAA license. I am somewhat surprised that they did not quote the relevant part of EU air law - but perhaps it's just as well...

(...) flying an N-aircraft will always require an EU license in addition to the FAA certificate if you are an EU resident.
IAOPA Europe

Residents of the European Union, by the terms they accepted to gain the right to residency or by the fact that a national citizen has the obligation to abide by the laws of his country, have the obligation to follows the laws relevant to their residency location.
So, in addition to the licenses and qualifications necessary to conform to the laws and rules of the country of registration of their aircraft, pilots shall also carry the same licenses and qualifications from the region where they elected to reside (...)
AOPA Luxembourg

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text:
How do I use the "Inoperative Components or Visual Aids Table" when more than one component is inop?
I can't fully seem to understand this sentence:

If more than one component is inoperative, each minimum is raised to the highest minimum required by any single component that is inoperative

Can someone please explain this for me? Perhaps using a scenario with an approach where some equipment is inoperative?

I believe it means your RVR would be 4500 and your visibility would be 1/2 mile since those are the maximum values for any single failure.

It means that in case of more than one inoperative component, the additions are not cumulative.  For example, if a particular ILS is authorized for 1800 RVR, and the approach lights AND touchdown zone lighting are inop, the increase in minimums is the largest single penalty (to 4000 RVR).  You do not add the penalties for multiple failures.


text:
What is the maximum body weight allowed for a pilot?
What is the maximum allowed body weight for a new commercial pilot student?
Would someone weighing 130kg be rejected on the basis of health? If so, what should that person weigh to avoid the rejection?
I have read about regulations mentioning 75 kg + 10 kg for flight crews, but I doubt if all pilots fall under that category because I have seen many pilots who look heavier than that. But I need some professional advice on this regarding current commercial aviation.
I'm interested in rules in India, Canada and the USA.

In the US there's no specific weight limit in the regulations. Instead, they just say that you must be capable of performing the duties of a pilot, e.g. 14 CFR 61.113:

The general medical standards for a first-class airman medical
  certificate are:
[...]
(b) No other organic, functional, or structural disease, defect, or
  limitation that the Federal Air Surgeon, based on the case history and
  appropriate, qualified medical judgment relating to the condition
  involved, finds—
(1) Makes the person unable to safely perform the duties or exercise
  the privileges of the airman certificate applied for or held; or
(2) May reasonably be expected, for the maximum duration of the airman
  medical certificate applied for or held, to make the person unable to
  perform those duties or exercise those privileges.

But the FAA is concerned about some conditions that are strongly linked with obesity, like heart disease, diabetes or sleep apnea. Those could be an issue for getting a medical certificate.
Apart from the regulations, there may be some practical weight limits for other reasons:

Military pilots have much stricter medical requirements (I know you're asking about commercial pilots), partly because they have some special considerations
A very large pilot may be physically unable to fit into some cockpits and/or move the controls to their limits
A very heavy pilot may be too heavy to fly in some smaller aircraft (including training aircraft) because of weight and balance limitations

in the 727 at least, a big or tall pilot makes the flight extremely uncomfortable for the occupant of the front jumpseat. :D I speak from experience.

Some aircraft have, manufacturer imposed, weight limitations for occupants of some or all seats. Usually this is for the purpose of crash worthiness.


text:
What does ''NAV ILS OUT OF SERVICE'' mean?
Just curious about the NOTAM below:

!SMF 01/045 (KSMF A0080/19) SMF NAV ILS RWY 16L OUT OF SERVICE
  1901180419-1901262359

Does that mean only the glideslope is broken so we can still do a LOC approach, or are both the localizer and glideslope broken?

It means exactly what it says. The ILS is out of service, so you can't use it.
An ILS can consist of several different elements, for example localizer, glidepath, DME, inner/middle/outer markers as well as a bunch of technical monitoring equipment, ATC control panels, warning systems and backup power supplies. Should any of these components fail, it may be required to take the entire system out of service. The NOTAM doesn't say exactly which part of the ILS is broken, but that doesn't matter, since the entire ILS is listed as unavailable. So no, you cannot expect to use the localizer.

Also, there's a difference between "not permitted to be used" and "not able to be used". The equipment might actually be powered up and transmitting usable signals when you arrive, but until it's "in service" you're not permitted to use it for navigation.

@SteveV. Very true. If, for instance, the monitoring equipment has failed, the LOC and GP may still be transmitting, but using them for navigation would not be allowed

GP OUT OF SERVICE is the verbiage used when only the Glide Slope is out of service, where GP is an acronym for Glide Path.


text:
Should I mention an altitude restriction from the previous controller during an ATC handoff?
I was flying my first solo cross country today with VFR flight following heading east at 5,500 ft. As I approach my top of descent (TOD), the controller nonchalantly said, "[call sign], you can descend to 4,500, if you want." So I replied that I would descend to 4,500. I got handed off to the next controller and told him, "[call sign] level at 4,500." He got somewhat annoyed that I wasn't at an odd-thousand-plus-500 foot altitude heading east, so I told him I would continue descending to 3,500.
My question is, how should I have handled this? Should I have told the new controller I was restricted at or above 4,500 even though the previous controller didn't explicitly say I was restricted (recall she just said, "you can descend to 4500, if you want").

Often they restrict your descent for other traffic. Looks like the other controller didn’t get the message. Nothing to worry about.

There is a bit of a misunderstanding as to what happened here

Should I have told the new controller I was restricted at or above
  4,500 even though the previous controller didn't explicitly say I was
  restricted (recall she just said, "you can descend to 4500, if you
  want").

You were not restricted to anything (assuming you were within any airspace limitations), flight following is not the same thing as being vectored. Sometimes on flight following you will hear something like

VFR Altitude At Your Discretion

When you are on flight following you are subject to ATC vectors when they are issued in controlled airspace (A,B,C,D and E) but you are also free to maneuver within the VFR regulations so long as you are not asked to hold a course or avoid a certain area or move for traffic etc.

you can descend to 4500, if you want

This was not an explicit instruction and not one you needed to comply with nor the floor to which you could come down to technically. They were saying there was no apparent traffic conflicts and if you (for what ever reason) wanted to come down you were clear to at least 4500 ft.
However there are some cases under flight following where you should comply with instructions. Im actually not sure what the legality is on this since you technically don't need to take FF in which case "see ad avoid" is your responsibility. But on any note I have received something like

Turn left 20 degrees for traffic climbing out of 2500 for 8000

In my experience flying trainer sized stuff in the congested north east corridor, flight following (which ultimate often comes from approach control in this area) will vector you out of the way for jet traffic. Strictly speaking this has occurred in class E airspace where VFR aircraft are largely free to do as they wish.

You may have also been handed off to an angry controller, but you should stick to VFR cruising altitudes when possible as per § 91.159.

Unless we know where the OP was flying, they may not even have been subject to 91.159. That regulation only applies to altitudes of 3000 feet above the surface, so for example around Denver, you wouldn't have to comply with the even/odd rule until at least 8,000 feet. The OP was also authorized by ATC to decend to 4500, so even if it did apply, ATC authorized a lower altitude. This was the controllers fault, not the pilots.

@RonBeyer My understanding is that under flight following you can ascend and decend at your own discretion (without clearance) although its generally a good idea to ask first. I often get the "vfr decend at your discretion" when on FF asking for a lower altitude.

That is correct, you are VFR and flight following is just radar separation service unless you are in airspace where you are controlled (like around an airport). I've done it both ways (just adjust altitude and ask) and nobody has ever said anything when I "just did it", but when asking I get anything from "approved" to "N12345 you are VFR, altitude your discretion" (with the overtone of "don't ask me again").

"you are not subject to ATC vectors unless you are in Class B, C or D controlled airspace" is not correct. Remember that class E is controlled airspace, therefore per 91.123(b) you must comply with all ATC instructions. See the Karas interpretation for explicit confirmation.

@Pondlife Interesting, I have adjusted accordingly

@Pondlife - that should have been an answer...

@jwzumwalt I don't think my comment really answered the question about communication following a handoff.

@Pondlifw missed a few words I think it's good now

Not sure why that controller was grumpy except that some controllers are always grumpy. Just say '[previous] center' cleared the descent to 4500.


text:
Why would one cylinder on a Continental O-200 run cold at idle?
I have a Luscombe with a Continental O-200 engine. The #4 cylinder is running cold at idle, does anyone have an idea why? The other three cylinders are running fine.
Some extra information:

The engine has only 300hrs SMOH but it hasn't run for two years and it's just had some maintenance work done (carb, filters, plugs)
Cylinder #4 is cool to the touch, the others are too hot to touch
A mag check seems normal (expected RPM drop on both mags)
A compression check seems normal (76/80 on #4 cylinder)

A: Idle circuit is set too lean and the cold jug is not firing.
B: Intake leak, causing same condition as A.
C: A little of both.
I know that a lot of people will lean out their idle mixture, by adjusting the screw on the carb, to reduce plug fouling with 100LL fuel (since leaning with the cockpit mixture doesn't do anything in the idle range).  You can tell when this has been done because the engine doesn't have the little RPM bump when pulling idle cutoff, and also it may require extra prime to keep running when cold.
Also, please write your questions with a bit of structure and grammar.  That stream of consciousness no-grammar style (that a lot of people use in emails out of laziness) is a total pain to read and interpret.

Idle adjustment set perfect, intake manifold to carburetor gasket brand new,  and as improperly noted in my question I'm replacing all rubber's for intake tube's.

Do apologize for the sloppy grammar been very sick and loopy on pain medication

No worries. Not to say you need to write arduous essays, and brevity is much appreciated, just use enough caps and punctuation and structure it to make it easy to follow.  Hope you are feeling better.  Anyway,  it runs fine at higher rpms?  Also does it misfire the same with carb heat on (slightly richer mixture)?.

Yes ran up to 1800 rpm and did a mag drop sounded perfect.  I did not do carb heat because cowl is off and so is the ducting.

Sure sounds like an intake leak that only happens at low MP where the suction is highest, like from a crack in the rubber intake tube.


text:
Do (or can) pilots observe religious fasts when flying?
This question is about religious fasts like the Muslim Ramadan and others.
Is there a civil aviation regulation about this? Must a pilot eat and drink by the regulations (or abstain from flying), or is this an issue left to the pilot's personal decision?
Obviously if a flight takes long hours and the pilot can't eat and drink, or abstained from eat and drink for long hours before the flight, this can affect the pilot's performance. I don't know enough to say if it can actually impact safety but it is obvious that the claim would not be far fetched.
How is this issue addressed in airlines? For example in Muslim countries where I would expect a significant number of pilots to be Muslims, if a religious fast is widely observed this could be an issue.

under which jurisdiction? for example, Saudi law might be quite different from the US one.

For the FAA, it would be covered under FAR 117.5 which requires that each required crewmember positively affirms that they are fit for flight by doing something like in AC-117-3.

Aren't travellers exempted from the Ramadan fasting requirements? This is a "heard from a friend" (who had lived in Saudi Arabia) sort of reference, but he said that those who were travelling weren't required by the Ramadan rules to fast. Many Terry can confirm?

The use of the word civil rather than federal suggests UK law but would be good to get answers from some major authorities around the world.

@Notts90 "Civil aviation regulations" just means "regulations concerning civil aviation" (as opposed to "regulations concerning military aviation.") The term is used more or less worldwide, including in the name of the worldwide organization intended to coordinate such regulations between countries, the International Civil Aviation Organization (ICAO.) The term doesn't really suggest any particular country's regulations in itself.

@RalphJ https://islamqa.info/en/answers/37717/how-should-a-cabin-crew-member-fast  So long as you are working as a member of the cabin crew in an airplane, you are travelling, and the scholars are agreed that it is permissible for the traveller to break his fast during Ramadaan, whether it is difficult for him to fast or not. This is a Sunni (mainstream) Islam source, which frequently refers to well known mainstream scholars.

There is no general answer for this question. Do pilots observe religious fasts during flying? Some do, as this article notes:

... although Islam gave permission or leeway to break fast if one found it tiring during the flight, most pilots and cabin crew still chose to fast.
“So, I fasted for 10 hours 50 minutes, compared to 13 hours 42 minutes in Kuala Lumpur and 11 hours 11 minutes in Melbourne. Much shorter time than fasting in Melbourne, isn’t that interesting?
“However, on June 29, 2016, I will be flying to Jeddah. Jeddah residents will be fasting for 14 hours, 54 minutes while KL residents will fast for 13 hours 43 minutes. I will probably have to fast for 17 hours! This is when I have to be really patient. I may break my fast once I have landed.
For the safety of passengers and to ensure a smooth flight, if both pilots are Muslims, they take turns to eat, he said.

However, there is no way to tell for certain how many aircrew observe religious fasting, as this pilot may be talking about that particular airline, for example.
As for Can they observe religious fasting, it depends on the regulation and company policies. Most of the civil aviation authorities don't have anything specifically related to religious fasting, preferring to cover them under fitness for duty, though there is atleast one case where the regulatory authority explicitly forbid fasting.

Indonesia’s Directorate General of Civil Aviation ruled that all safety-sensitive aviation personnel must eat while on duty during Ramadan, the Islamic month of fasting

Yes, they can fast, and it appears that many Muslim pilots are doing it. There is no explicit rule forbidding it. Pilots are required to maintain their working ability, but this leaves some room for interpretation.
On the other hand side, there are exceptions that allow Muslims to suspend fasting under certain circumstances. One of these rules concerns travelers. If such an exception is applied, the person is required to make up these days after the official end of the Ramadan. Many Muslim pilots actually do suspend Ramadan during their duty.

can you provide a source for your statements?

@Federico Yes, easily for the second paragraph. If one does not believe the first sentence, it is very easy to find numerous statements in the internet.

@Jenc - "easy to find on the internet" is not really what we're going for at the SE sites. The preference is to have the information here with a link to the source (since sources can go dead at any time).

you're still missing references for - "Many Muslim pilots actually do suspend Ramadan during their duty." - "There is no explicit rule forbidding it." (have you checked all possible jurisdictions?) - "many Muslim pilots are doing it"

Although this answer seems quite good, it may still be improved by adding links and references to support your answer and also to provide further reading.

I will add references asap.

@Jenc have you found your references?

The first thing that comes to my mind is the IMSAFE checklist; as a Private Pilot who practices intermittent fasting, I don't see why fasting would be an issue, as long as they can safely perform the tasks that they are required to complete, to the standards that the FAA expects.

"I don't see why fasting would be an issue". From Journal of the Royal Society of Medicine, a UK publication:  "Ali showed that fasting reduced cognitive function and explained this in terms of physical fatigue. These results clearly have implications for long-distance drivers, people operating machinery, and the like. [...] A study of road traffic accidents in Saudi Arabia showed a significant increase in the number of accidents during the period of Ramadan."

Thank you for pointing that out! You may also be interested in this article ("[...] the body has been optimized to perform at a high level in the food-deprived state[...]"), or another that suggests something similar ("This metabolic switch [...]is accompanied by [...] adaptations of neural networks in the brain that enhance their functionality"). I think the jury is still out on this, but it should be noted there are different types of intermittent fasting. It will have its greatest negative impact if you are not used to it.

I'll add another resource -- particularly point 8 -- for anybody else who is interested in this conversation in the future


text:
Does Autopilot make planes safer?
Statistically, are planes with advanced autopilot functionality less likely to be involved in fatal crashes? Answer only with actual statistics, not your personal opinion.

This is a very broad question to which there exists no single correct answer. I suggest you have a read here: https://www.eurocontrol.int/sites/default/files/publication/Hindsight/Hindsight-20.pdf

@J.Hougaard: Can you provide an overall idea of why the number of incidents/accidents could increase with some automation equipment? It seems the bottom line is positive, as automation continues to be implemented, and the number of accidents continues to decrease. Perhaps this is only a matter of appropriate training to take over automation when it fails?

@mins You can train for taking over when automation fails, but staying proficient will be nearly impossible because you only get a fraction of the hands on experience you would if you were doing everything manually. Case in point: AF447

@J.Hougaard, agreed. I was only emphasizing that increasing safety doesn't mean removing all accidents, nor preventing accidents for new causes created by automation, just the number of cases decreases. Since the car safety belt has been mandatory, people likely died because of the belt, perhaps drowned in water,  but driving with a belt is still safer overall. AF447 is indeed one of these cases.

The answer is definitively yes if well-understood and used properly.

Voting to re-open. It's an interestimg question: automation helps flight economics, does it also improve safety. Perhaps the community knows of a study that indicates this.

You might want to check out this NASA report on the effects of autopilot use in single pilot IFR.

The autopilot is as safe as we programmed it to be. The more factors the autopilot can factor in the safer it will be. But I think the real difference between safety occurs when something abnormal happens to the aircraft like broken control wires making the controls very unpredictable. A human can understand this or at least try. To make a computer capable of this is very very hard. In daily operation a computer does not make mistakes if properly programmed. A human is susceptible to skip steps by mistake in routine work.

Using e.g. Boeing's annual commercial aviation safety statistics, one can essentially show that with each new aircraft generation, the accident rate reduces. This answers your question about statistic involvement, but doesn't really confirm a causal relationship, since it's not only automation but e.g. also human machine interface (flight deck) design and system architecture that improves. However, I would assume there are quite probably at least some safety improvements due to automation in there. One would need to go about analysing the accident factors to prove this.
As an interesting aside touching on this topic, a former colleague of mine flying commercial jets recently offered his first-hand view on different aircraft automation levels in his blog.
While not a comprehensive answer as such, I hope the links allow you to pursue this a bit further.


text:
What was this mystery flash on an airport runway?
Recently I was onboard a commercial airliner and we had just landed and were headed for the gate. I cannot remember exactly which airport but it was either Schiphol(Amsterdam Airport) or Bristol. As we were taxiing I was looking out of the window and saw an object(?) fall vertically into my eyeline from about 10 m up. This object was maybe 50 m away and was at the edge of an intersecting adjacent runway/road and the grass. I noticed it because it had a faint trail of smoke emanating from it. At around 3 m above the ground it ignited, there was a short white flash and it made a small white cloud of smoke that lingered for a short while.
Does anyone know what this might have been? It was almost like a flare/firework (which makes no sense at an airport) so is there another explanation?

This seems to be a dupe of this question, although arguably this one has better answers right now.

"At around 3 m from the floor it ignited".  Or the ground?

Bird / Passenger scarer. :-)

@RonJohn The ground

@Dannie Can't vouch for the birds but can confirm it was a passenger scarer

It's likely to be a flare / flash bang for bird control. Schiphol uses these (amongst a wide variety of methods).

Bird dispersal equipment
There are various resources a bird controller
  can use to keep birds away from the runways. Standard equipment
  includes a flare gun with noise blanks, a bird alarm call system and a
  green laser.
The flares and noise blanks come in various types,
  including a number of ‘whizzers’. The flare used depends on the bird
  species and the number of birds the controller wants to scare away.
  Some species respond better to a loud bang and others to a screeching
  noise. Bird controllers also have all the most common bird alarm calls
  at their disposal, which act as a warning for the other members of the
  species to leave the area as soon as possible. All bird controller
  vehicles are equipped with a mobile green laser. This is a type of
  torch that emits a green laser beam to chase water birds away from the
  surrounding ditches.

Source: Schiphol Bird Control information brochure
At Schiphol the Bird Control vehicles are equipped with ADS-B. This makes them visible on flightradar24. If you remember the day of your flight, you maybe able to see if they were operating in the area near your taxiing aircraft. The cars have callsign Kievit (peewit / lapwing) and use abbreviation "KV#" as flight ID on ADS-B.

Trivia: they're probably called Kievit because their primary purpose in the 70's was moving the native kieviten from the landing strips to safer areas. They have radar on board and equipment to produce the angry sounds from up to 42 types of bird.

@Mast So they literally make angry birds sounds?

@Michael Technically the sounds are the equivalent of what birds of those species would make to warn for danger, sending the birds away. But, yes.

Likely a flash-bang for runway bird control.
Birds on and near the runway are an ongoing major safety problem (witness the "Miracle on the Hudson", an A320 brought down by a flock of geese shutting down both engines).  Measures to convince them to go elsewhere are only ever temporary and of limited effectiveness.
One of the measures that is commonly used is launching what amount to large firecrackers out of air cannon.  The launchers have enough range to be placed out of the way of aircraft traffic, but can reach the whole field (and the aim doesn't need to be terribly precise, they won't be fire when there are actually aicraft in the target area).

Thanks, @Bianfable.  Corrected.

From what I can remember seeing, this explanation seems perfectly plausible!

@NathanThomas Also see DeltaLima's answer, it's specific to Schipol.


text:
What could lead to engine running hot on climb out?
I own a turbo Saratoga with an intercooler and gami's. The engine has 100 hrs so it is broken in and I can't get the cylinder head temps below 400 during my climb out and I am operating at full power.
This has required me to run a very low power setting to keep the temp below 400, but my climb rate is terrible.
I am running full rich from take off thru climb.
Does anyone have any ideas on what the problem might be?

How does the fuel flow compare to the book value? The book says my TSIO-520H needs 120 pph and that’s about what I see. It is possible that even though you are at full rich, you aren’t getting the fuel flow necessary to keep the engine cool.

I'll provide a bit of a general answer to this so it covers for most cases. The basic question is, "my engine is running hot on climb out, what issues could lead to this"
Cooling Air: Airplane piston engines are air/oil cooled and require proper airflow over the engine to cool properly. A poorly installed cowling or obstructed/damaged air inlets can cause airflow to be incorrect. Some aircraft also have some internal baffling to direct air around the engine bay, these parts can move or get out of place and may be causing improper flow.
Fuel: As JScarry mentions, you need to ensure you have proper fuel flow (which is key to temp control). If you don't have a flow meter installed a shop should be able to check this for you.
Procedure: This sounds like a new plane to you, are you following all book procedures for climb out? Turbo planes often have different op-specs than their NA counterparts. Its not uncommon for there to be full power limitations (e.g. full power 5-min continuous limit then reduce to XX MAP).
Timing: You may have a faulty magneto or your magnetos may be improperly timed causing an advanced ignition situation that would add stress (and heat) to the engine.
Auto-Turbo Settings: I believe the Turbo Toga's had self governing turbos but not all planes do. You should make sure the pop-off mechanism is set correctly and the turbo is operating with in its proper limits.
Set-Up: This is unique to your new engine case but it may be worth bringing in another A&P that is familiar with the Toga Turbo engine and set up to make sure everything is where it should be just in case the engine shop overlooked something.
Incorrect Indication: To add to "Set-Up", it's possible that your CHT is incorrectly calibrated or installed. (this is an edit from another poster, who experienced high oil temps to finally discover that the oil temp thermocouple was in the wrong location, and read higher than actual temps)

More on what Dave said on fuel and procedure. If you're running a less-than-MCP climb, are you doing this just with prop, or with throttle (or throttle and prop)? Full (or MCP) throttle manifold pressure includes an extra-rich fuel flow. If you're reducing power by reducing manifold pressure, you might be decreasing the fuel flow outside the extra-rich range. (That said, I'd look at cooling air first. And probes: you could have a faulty CHT probe, or faulty CHT gauge.)

What's your gami spread?
Do you have a multiprobe engine monitor?
Do you leave the MP and RPM at maximum allowable settings (could be full forward) or do you use some sort or reduced setting (ex. 25/2500)?
Are you following POH guidance?  If you are you are probably doing more harm than good.  POHs are notorious for providing sub-optimal engine guidance.
I bet good baffles and a little more fuel will solve your issue (or at least help).
First, the redline on your fuel flow is not a maximim, it's a minimum.  Bump the flow up a little bit.  If your IA says that is illegal you need a new mechanic.  It's not illegal.
Second, check the baffles.  You may need to install new ones.  If you have leaky baffles on a TC engine you are asking for trouble.  How old are they?
John Deakin - this is the name of an engine guru.  Read everything you can about engine management by this author.  He writes the Pelican Pearch series and gives very good, research based guidance.
Mike Busch - also very knowledgable.
Where are you located?  Dry desert or humid coastal?


text:
Why would my transponder interfere with my ADF?
The ADF in my plane works very well until I switch the transponder to ALT. At that moment, the ADF needle is stuck in a random position and will not show the direction to the selected NDB anymore (the transponder works flawlessly).
Where is the interference coming from? Is it because the two boxes sit on top of each other on the dashboard? Or is it due to a bad placement of their respective antennas on the fuselage? Would seem strange to me, as their respective frequencies are far apart (kHz vs. MHz).
Any norm / guidance on how to install these two systems so that they do not interfere with each other?

What are you getting on the ADF's audio channel when they are both on?  I might take an AM radio and move it around the units and coax runs listening for odd broadcast sounds.  The xponder or its antenna cable is radiating low freq RF somehow.

I finally got a chance to do some additional checks. Listening to the audio channel, I can clearly hear the morse code for a given NDB. Switching the transponder to ALT does not modify the audio (at least in a way that I can notice). The problem is also not apparent for all NDBs. I checked with more of them (different frequencies and ranges), and only one was being followed correctly when the transponder was on.

ADFs and transponders are often right next to each other in the dashboard, it's not the placement that's the issue. The two systems work on different sets of frequencies, so antenna placement shouldn't be an issue. If the ADF is being getting interference from the transponder in ALT mode the most likely issue is that one or the other is malfunctioning, or there is a short in the wiring between the two systems.


text:
What does SVC TAR/SSR U/S mean?
Looking through NOTAMs. What does SVC TAR/SSR U/S mean? Does that mean I cannot shoot practice approaches in the area?
Here is the NOTAM text:

07/052 (A0474/17) - SVC TAR/SSR U/S. 21 JUL 12:00 2017 UNTIL 21 JUL
  17:00 2017. CREATED: 20 JUL 12:08 2017

07/052 (A0474/17) - SVC TAR/SSR U/S. 21 JUL 12:00 2017 UNTIL 21 JUL 17:00 2017. CREATED: 20 JUL 12:08
2017


text:
What does aileron droop help to do?
Aileron droop helps to:
A - prevent upfloat
B - correct adverse yaw
C - get control feel
D - compensate drag
Please mention the most appropriate choice and only one correct answer. With a brief explanation if possible!

Welcome to aviation.se! what do you need help with? why are you not able to choose the correct answer?

Your choices:

a- prevent upfloat: droop is the reverse of upfloat. Upfloat is useful in reducing adverse yaw.
b- correct adverse yaw: no, upfloat does that.
c- get control feel: yes there might be some increased aeroforce feel gradient around neutral. Around zero deflection it takes a little while before the aerogradient picks up, creating very light forces in an area where good force feedback is important. Droop helps to reduce this, since both ailerons are sticking in the wind already.
d- compensate drag: no, droop creates drag.


text:
What would the pros and cons be of this 'zig-zagged' high-sweep wing planform?
What would be the advantages / disadvantages of the following wing planform for supersonic aircraft?

The suggested planform is in red; a more conventional, delta planform is illustrated for comparison in white. I was wondering if a zig-zagging leading edge would increase efficiency at high speed due to the increased leading edge sweep without a decreased aspect ratio. I was also wondering if improved control at high angles of attack would be an added bonus, like the "dogtooth" on the F-4 Phantom. I suspect that reduced structural strength could be a disadvantage.

Equalizing the cross section will be difficult. And it loses the structurual advantage of a delta to be light weight.

@user3528438: Just what I thought: you'd have to make the pointy triangle part a lot stronger, or else it would just fold back.


text:
What minimum radio communication equipment is required in a homebuilt aircraft in India?
Let's say I am building a single seat aircraft for flying in one's own country(India). What should be minimum set (Not only from compliance prospective but to have core set of communication for security and safety reasons with ATC or other receivers ) of things I must have on my aircraft?
Background : We are planning to provide this set of Radio systems for Hobby Aircraft builders.
Update : As per the answer, It is cleat that one do not need to have radio system always in the flight.

The minimum equipment required (if any) will be defined by the DGCA regulations. The minimum equipment that pilots want (and are prepared to pay for!) may be different. It seems that there's at least one EAA chapter in India, and they might be a useful source.

According to DGCA Rule 63 you need a radio onboard to operate both VFR and IFR

63. Aircraft for which radio apparatus is obligatory-
(1). All aircraft registered in India and required to be operated in accordance with VFR/IFR condition shall be provided with communication equipment which
  is capable of conducting two-way communication at all times with those
  aeronautical stations and on those frequencies as prescribed by the
  appropriate authority. The communication equipment so provided shall
  be of a type approved by the airworthiness authority of the country of
  manufacture of aircraft and acceptable to the Director General.
(2).   An aircraft shall be provided with navigation equipment which will enable it to proceed :
(a)   in accordance with the flight plan; and

(b)   in accordance with the requirement of air traffic services, except
      when, if not so precluded by the appropriate authority, navigation for
      flights under the visual flight rules is accomplished by visual
      reference to landmarks at least every 110 kms (60 Nautical Miles).

DGCA Rule 9 also adds some stipulations to the operation of the radio its self

9. Radio-telegraph apparatus -
(1) No person shall operate radio transmitting apparatus in any aircraft registered in India unless he
  holds a licence of the type required by the provisions of Part V in
  respect of aircraft required by these rules to carry radio-telegraph
  or radio-telephone apparatus, as the case may be, and issued in
  accordance with those provisions.
(2) Radio-transmitting apparatus carried in aircraft shall be operated
  under the conditions defined by the International Tele-communication
  Convention (Madrid, 1932) and the general radio-communication
  regulations annexed thereto as far as these apply and shall be
  operated only during the hours in which such operation is permitted by
  the Central Government.
(3) Aircraft registered in India and required by these rules to carry
  radio-telegraph apparatus shall be fitted with such apparatus in
  accordance with the provisions of Part VII.
(4) Nothing in this rule shall exempt any person from those provisions
  of the Indian Telegraph Act, 1885, and the rules made thereunder which
  require that radio-telegraph apparatus shall be licensed.

You can find the rest of the rules here. I went through them briefly and cant find a whole lot on certifying home built aircraft. Or what rules they would actually fly under. There is a short list of things related to actually getting an airworthiness cert here but it does not touch on VFR/IFR classifications related to that.

As for the safety aspect of it, that depends on your countries aviation infrastructure and if carrying a radio benefits you. If no one is listening on the other end then its not going to add much but weight to the aircraft. From a regulatory standpoint you may need it to enter certain airspaces (you may also need a transponder for that as well) I cant find a whole lot on the DGCA website about airspace regulations so its hard to say exactly when you would need one. I can only compare it to places I have flown and here in the US while you don't legally need a radio in uncontrolled airspace its still a good idea to have one and to use it as you should (CTAF announcements, flight following if you like, 121.5 if you need it etc.)

The minimum? Nothing.
Requirements may be different in each country (but I'm fairly certain this is standard throughout the world) here in the U.K. there is no requirement to carry a radio in an aircraft - this of course limits which airports you can fly into and which airspace you can fly in.

I don't see how this answers the question, which is about equipment requirements in India. If you can link to the Indian regulations or another reliable source, that would be helpful.


text:
Is right rudder always needed during go-around/touch and go with a Diamond DA-40?
Is application of right pedal always necessary in parallel with advancing power lever in diamond aircraft (DA-40) during go-around/touch and go?

"More right rudder" is like a Flight Instructor's mantra, for most all small single engine planes where the propellor spins clockwise from the pilot's viewpoint, and right rudder is needed when engine power is suddenly increased to counter the engine torque and airflow effects.


text:
What does this A320 FCTM quote about cold weather and non-precision approaches mean?
Can someone explain this paragraph from the A320 FCTM about minimum temperatures for non-precision approaches? I can't understand it.

COLD WEATHER OPERATIONS For all Non Precision Approaches, there is a minimum OAT. Below this temperature, the error on the barometric
  altitude is no longer acceptable, and altitude should be corrected in
  temperature. As it is not authorized to make these altitude
  corrections to the final approach segment of the FM Flight Plan
  (F-PLN) through the MCDU, it is not possible to use FINAL APP when OAT
  is below this minimum OAT. The flight crew must then use selected
  vertical guidance. This minimum OAT is indicated on the approach chart
  or must be defined by the operator based on the terrain profile (plus
  adequate margin).

Can you tell us which part you don't understand? This question explains the background about cold weather and approaches, but not the avionics part.

I am surprised that there is not a max OAT, as that can be a factor as well.

well, high OAT will just put you higher, so that's not really considered a big issue. other than a little extra energy descending on final you should be fine

I am not sure which part you don't understand, but here is my attempt to explain in more laymen terms.

Short version: When it is too cold, a certain mode for flying non-precision approaches using the Airbus flight computer cannot be used. This is because the altimeter reading is inaccurate when it is too cold, but the computer is not designed to compensate that.

Long version: For all non-precision approaches (i.e. approaches where ground equipment is not providing glideslope signal), there is a minimum Outside Air Temperature.
Since the reading of the barometric altimeter is affected by temperature, when it is too cold outside, the reading can no longer be considered accurate enough for the safety of flight. Corrections should be made (using a mechanical flight computer / lookup table / other tools) to convert the indicated altitude on the instrument to the reading it would have indicated under normal temperature.
Since it is not authorized to make these corrections in the autopilot computer, it is not possible to use the "FINAL APP" mode to fly the approach when the outside air temperature is below this minimum.

I see got it


text:
How does SLATS/FLAPS retraction damage the RTLU mechanical stop if we retract them after the ADIRS are set off?
From the A320 After landing FCOM NORMAL PROCEDURES:

To avoid damage on the RTLU (Rudder Travel Limit Unit) mechanical
  stop, the SLATS/FLAPS should be retracted before all ADIRS are set to
  OFF simultaneously.

What happens if the SLATS/FLAPS are retracted after the ADIRS are set to OFF? How will the RTLU be damaged?

According to this PPRuNe thread, the problem is not the retraction of the slats/flaps but instead turning the ADIRS (air data inertial reference units) off. The RTLU is designed to operate in a feedback loop, where its position is controlled based on input from the FACS (Flight Augmentation Computers, which take input from the ADIRS). If the ADIRS go offline while the slats are extended, the RTLU goes into a "emergency return to low speed" mode. This allows maximum rudder travel by driving the RTLU to mechanical stops. If this happens regularly it can cause damage to the stops.
This appears to be related to the Indonesia AirAsia Flight 8501 crash. Although this issue was not one of the main contrbuting factors, the report lists this as one of the Technical Followups (TFUs) that Airbus issued as a result of the investigation. It improves the reliability of the RLTU, the failure of which was cited by the investigation.
See this related question for more on the function of the RTLU in the flight control system: What are the “channels” on the A320 Rudder Travel Limit Unit?


text:
What are the FAA's requirements for an experimental type certificate?
What is required by the FAA to obtain an experimental type certificate for a manned prototype aircraft?

Found it. It's easy to get lost in the FAR's, but in case you're curious I managed to find the requirements I was looking for under 14 CFR 21.193:

An applicant for an experimental certificate must submit the following
  information:
(a) A statement, in a form and manner prescribed by the FAA setting
  forth the purpose for which the aircraft is to be used.
(b) Enough data (such as photographs) to identify the aircraft.
(c) Upon inspection of the aircraft, any pertinent information found
  necessary by the FAA to safeguard the general public.
(d) In the case of an aircraft to be used for experimental purposes—
(1) The purpose of the experiment;
(2) The estimated time or number of flights required for the
  experiment;
(3) The areas over which the experiment will be conducted; and
(4) Except for aircraft converted from a previously certificated type
  without appreciable change in the external configuration, three-view
  drawings or three-view dimensioned photographs of the aircraft.
(e) In the case of a light-sport aircraft assembled from a kit to be
  certificated in accordance with §21.191(i)(2), an applicant must
  provide the following:
(1) Evidence that an aircraft of the same make and model was
  manufactured and assembled by the aircraft kit manufacturer and issued
  a special airworthiness certificate in the light-sport category.
(2) The aircraft's operating instructions.
(3) The aircraft's maintenance and inspection procedures.
(4) The manufacturer's statement of compliance for the aircraft kit
  used in the aircraft assembly that meets §21.190(c), except that
  instead of meeting §21.190(c)(7), the statement must identify assembly
  instructions for the aircraft that meet an applicable consensus
  standard.
(5) The aircraft's flight training supplement.
(6) In addition to paragraphs (e)(1) through (e)(5) of this section,
  for an aircraft kit manufactured outside of the United States,
  evidence that the aircraft kit was manufactured in a country with
  which the United States has a Bilateral Airworthiness Agreement
  concerning airplanes or a Bilateral Aviation Safety Agreement with
  associated Implementation Procedures for Airworthiness concerning
  airplanes, or an equivalent airworthiness agreement.
[Doc. No. 5085, 29 FR 14569, Oct. 24, 1964, as amended by Amdt. 21-85,
  69 FR 44862, July 27, 2004]


text:
What’s the difference between a tail number and a Manufacturer's Serial Number?
What’s the difference between a tail number and a Manufacturer's Serial Number (MSN)? How and when are they generated?

The tail number is the civil registration, and the manufacturer serial number (MSN) is a build number used by the manufacturer.
It is similar to the licence plate on your car, and the vehicle identification number applied by the builder of the car.


text:
Why aren't push propellers common on wing engines?
The only push propeller designs I know of are centerline/fuselage mounted which has obvious problems as far as having a tail on the rear of the aircraft.
It appears these challenges lead to all the push propellers I know of either being twin boom back from the wings to each end of the tail (Cessna Skymaster), or being canard aircraft so the tail swaps spots with the engine and the plane is "backwards" (Velocity XL, Rutan Long Ez, Rutan VariEze).
And yet, there is a lot of multiengine aircraft out there with one engine on each wing (see Beechcraft Baron, Cessna 310, lots of others). Those would sidestep the tail conundrum.
Is it possible or even reasonable to have pusher props on wings? What are the disadvantages? There must be a reason that we don't see every twin prop airplane (with an engine on each wing) with a pusher configuration! Are they just less efficient? Or have some dangerous "edge of the flight envelope" problem? Or present some hard engineering challenge?

I wouldn't call the Starship "current" -- last I heard there were only two left flying and they were dependent on a boneyard for repair parts.

This should also help.

Yes, the Velocity 173 RG-E is certainly very sexy looking, but lands at 70 knots and flies on 200 hp.  Much of the performance improvements on the "Starship" types came from weight savings from use of composites.  OK, let's reduce the wing area of the Cessna 172 by 1/2, have retractable landing gear, and put the 200 hp engine on with 60 gallons of fuel.  It'll land at 70 knots, with similar cruise performance, though the Velocity, with newer materials and lower aspect, will be a bit stronger.  Better yet, put the engine in front of the Velocity, then see.

@RobertDiGiovanni A Vans RV-7 gets similar numbers on similar power in a "normal" config design. After comparing a Cherokee 180 and an RV-7 I'm under no illusion that the trainer airplanes are really optimized for cruise performance. Heck, look at what a 160 HP RV-9 does, and it's cruise vs stall!

@ZeissIkon Beech 2000 is current as in currently operational. Sadly it's no longer in production, I love that design and miss seeing them (I've seen one a few times in the past).

Is it possible or even reasonable to have pusher props on wings?

Yes, absolutely! If you strive for the highest efficiency, pusher propellers are a good solution. When Convair was tasked in 1941 with developing a bomber which could reach Europe from bases in the US, they decided on a pusher design. But they come at a price.
Advantages of pusher propellers:

The prop slipstream can flow off freely.
Clean leading edge, uninterrupted high-lift devices.
No accelerated flow around the wing, therefore less drag.

Disadvantages of pusher propellers

Long driveshaft between engine and propeller, or, alternatively, a heavier engine mount to transmit the forces from the engine to the spar.
Depending on engine location: Less flutter damping due to the backward center of gravity of the propulsion system.
No blown flaps.
Propeller must go through the wing wake, no clean inflow into the propeller.
Heavier engine installation due to driveshaft and interference with wing structure.
Cooling of the buried engine is more tricky.

Why does the driveshaft have to get longer?

@Michael You want to mount the engine close to a strong structural element, and in a wing that is obviously the wing spar. Since this is located at maybe 30% or maximum 40% of chord, the distance to the pusher propeller is larger than in a tractor arrangement. Alternatively, if you mount the engines at a distance to the spar, the engine mount will weigh more.

Why is the wing spar so far forward? I thought that it is specifically to accommodate the heavy engine. So in a rear-engine wing design, the wing spar would be towards the trailing edge, no?

@dotancohen The spar should go where the airfoil has its biggest thickness. The tapering rear part would make a spar structurally inefficient.

I see, thank you. Makes sense.

@dotancohen: spar goes as close as possible to the load that it has to support in order it to be as light as possible. For a subsonic wing this is more or less 25% of the chord.

Does it mean that it's also more difficult getting out of a stall situation when the propeller is behind the wings?

@U.Windl Not necessarily. Especially when all props turn in the same direction, tractor props will force a nasty rolling moment on the wing that is absent in pushers. A stall with pusher props will be more symmetric but occurs at a slightly higher speed because the accelerated flow over the wing of a tractor is missing. OTH, the pusher will suck air from the rear wing, so separation will be delayed there. Details of stall recovery depend less on engine placement than airfoil and overall configuration, especially tail size and cg. location.

Some disadvantages of pusher props are:

propellers are operating in "dirty air" - the air flowing towards the blades has been disturbed by the wings, engine pod, fuselage etc. This will have an adverse effect on efficiency
the propellers are susceptible to damage from ice shearing off the wings and other "proceeding" parts. While this may not lead to instant failure, it is a consideration, and the magnitude of risk is dependent on the deicing method and procedures
depending on exhaust arrangements, the pushers may be louder. For example the Piaggio P-180 has a very distinct and arguably irritating noise signature because the turbine exhaust is being blown through the propeller blades.
depending on landing gear arrangement, pusher propellers may be more exposed to debris such as gravel, stones and dirt

From a very basic design point of view, the more prop/engine weight ahead of the wing means more fuselage and tail weight behind the wing.  This allows for for a longer, more streamlined fuselage and a smaller tail, offering a savings in weight and drag.
With wing mounted prop aircraft, putting the wing in clean air puts the prop in wing turbulence, although long range cruisers such as the B-36 Peacemaker, benefitted somewhat as their cruise airflow off the wings did not cause enough interference to significantly degrade prop performance.
However, a major concern with pushers became engine cooling, especially when piston engines grew to the size of the P&W R-4360.
For all purpose aircraft, running with higher power settings more often, the extra drag from opening cowling flaps for engine cooling greatly offsets any advantages.

oh bloody hell, I both read your answer wrong, and then wrote my comment wrong as well... :) I removed my comment.

I was just walking past a B-36 the day after this question was posted and was loving it. Of course I love the P180, so maybe it's me.

There are a couple of good examples of pusher aircraft with wing mounted engines. The Convair B-36, Beechcraft Starship, and Piaggio Avanti quickly come to mind.  I suspect the greatest reason is that in design of an aircraft it’s best to keep the engines and their respective fuel tanks very close to the intended center of gravity for stability reasons.  For the larger aircraft with greater CG ranges in size, the pusher design can work well, particularly for minimizing noise in the cabin. One advantage for tractor engines that are wing mounted is that you get a boost a lift from the propwash over the wings.  Some advantages to a pusher design, particular with turboprops is that you can use the engine exhaust to deice the propellers, so there’s no need for additional prop deicing equipment.


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After tuning and identify an ILS, do you mute the audio? How/where do you hear marker beacons?
I've practiced tracking an VOR radial in VFR conditions with a CFI. We tuned and identified the VOR, muted the Morse code, set the OBS, and then followed the CDI needle indications. I have not used a VOR that had HIWAS or flight service.  For me, there is some confusion on my part of if the Morse code identification and audio are separate encoded channels in the VOR signal that the radio lets you select between, or if the "PULL IDENT"* button on the radio is unmuting all audio.
My understanding is that ILS approaches (laterally/horizontally) are like a VOR, but with a much narrower width of coverage (and much greater angular sensitivity) than a VOR.
Working from that, I assume that when you use an ILS, you tune it, make sure your audio panel is configured to let you hear audio from the Nav radio you are using, and then you pull the "PULL IDENT" knob, turn it up if needed, and listen for the Morse code. Assuming that you get the correct code, would you then push the "PULL IDENT" knob to silence the Morse code? Or continue to listen to it for the whole approach? If you do mute the identification audio, are you then also muting the marker beacon audio? Or is that a different system entirely? Do pilots listen for marker beacon Morse code and pick that out from the identification Morse code, while hand flying an ILS approach?
*See the diagram on https://www.hodgeflightservices.com/wp-content/uploads/2017/11/Bendix-King-KX-155A-NAV-COM-Radio-Manual.pdf page 3 ("S1-5" on the PDF half pages), knob I'm talking about is labeled as number 8.

This depends on your aircrafts equipment but the VOR/LOC/ILS receiver is independent of the marker beacon receiver and monitored differently. The morse code identifier of the VOR/LOC/ILS unit tells you it is operating correctly and can be used while the morse code identification of a Marker Beacon tells you "you are overflying it".
The marker beacon audio comes over a the marker beacon receiver not the VOR frequency. The aircraft I fly all have Garmin audio panels which have MKR button (and a marker beacon receiver) that is used to select the marker beacon audio mode. This is independent of the NAV1 and NAV2 radio monitoring capabilities which bus the output of the nav radios to the headsets. Muting NAV1 or NAV2 does not effect the MKR setting.

(source)
Most of the audio panels I have encountered also have lighted displays for the marker beacons. The O M I will illuminate when the beacons are overflown. On the Garmin units this occurs regardless of the audio setting.

In all cases, the marker beacon lamps operate independently of any
audio selection and cannot be turned off. The GMA 340 can drive
external marker lamps if required.

FWIW the marker beacon system is being phased out in favor of GPS measured distance.
To answer the direct scenario

The radio is typically muted after the morse code identifier is received

Some of the newer glass systems will even display an ID on the panel when the morse code signal is received from the station so you dont need to identify it using the tones manually any more.

This does not impact the marker beacon audio or reception
You may choose to leave the nav audio on during the approach to confirm the system works for the whole approach but they are quite static-y and may get distracting if left on.
Some pilots will listen for Marker Beacon audio, I prefer the lights.

Note: The Pull Ident mode on most radios will only work if the appropriate NAV is selected on the audio panel as well but that will depend on your setup.

Saftey Note: With the way the modern IFR system works (at least here in the US) I would be very hesitant to fly an aircraft in actual IMC that did not have an IFR certified GPS unit which would make marker beacons more or less obsolete.


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What are the different steps to certify a new aircraft in Europe?
I know that to be allowed to fly an aircraft has to be certified by an agency and that this one is not the same for European or American (for instance) aircraft. What are the different steps that an aircraft designed to fly in Europe has to go through in order to be certified? Proof on the paper of some features? Ground tests (which one)? Flight tests (which one)?

It depends on the aircraft in question -- different aircraft are subject to different regulations by both the EASA and FAA.

The EASA certification requirements are all publicly available online. Actually proving that an aircraft meets those criteria will certainly include all the steps you mentioned although exactly what happens probably depends a lot on the specific aircraft and manufacturer.

It does really depend on where the aircraft is being designed and manufactured. The initial type certification is done with the authorities in the State of Design / Manufacture. If that country happens to be outside of the EU, EASA will identify what extra proof of compliance will be required to fulfil the European certification requirements.

For the most part, the EASA guidelines (as issued, for example, in Certification Memoranda, and the FAA guidelines (as issued in Advisory Circulars and in guidance to those acting for the certification authority, such as 8110.105) are pretty much harmonized.  (and that goes for the JAA as well.)  There are some minor spots whre EASA is either ahead of or behind the FAA guidelines; For example, there is a paragraph of EASA CM SWE?? - 001 [don't remember the exact number] (dated 2014) that deals with a small class of LRU issues and that is not yet in any FAA guidelines that I could find.
Even though the fundanentals are closely aligned, you still have to demonstrate compliance to the FAA authority after having been certified under EASA, and vice-versa.  However, since the process of obtaining certification pretty much demands attention to keeping your paperwork in order, your testing comprehensive and well-organized, and your certification artifacts available, once you have passed in one context the remaining work to be certified in the other is at least 90-95% in place.


text:
How do commercial airlines prepare for pilots falling sick during the flight?
According to this article, the pilot suffered a heart attack mid-air and a passenger helped in landing the plane safely.
How does commercial airlines prepare themselves for these kind of situations. Do they specifically check if there are any pilots in the passenger manifest and inform the crew and pilots beforehand? Or, do they leave it to the co-pilot to take care of such situations? Or do they fly in a pilot (like mid-air refuel)?
On digging deeper I found that pilot sickness has caused several crashes:

Continental Flight 3407 co-pilot felt ill before crash near Buffalo, transcript shows
Plane damaged, pilot felt sick: fatal Transwest Air crash report
Report into fatal plane crash in NWT shows plane was damaged, pilot felt sick

The article was a bit overblown, as if the passenger saved the day. In reality the flight would have landed safely with the co-pilot in charge.

Do they fly in a pilot? Only if Heston is available...

I agree with GdD. The article was more than just a bit overblown. The First Officer is more than qualified to fly that aircraft. I'm pretty sure she was more concerned with simply someone to help work the radios, as the article seems to indicate. Mostly it looks like Gongol is puffing his chest for the article. He did a good job assisting, but that's all he was: an assistant. It wasn't his place to "assess" the skill of the FO. I feel for the FO because she comes across as incompetent, which is apparently not even remotely the case. She was put in a bad situation and she responded very well.

@CGCampbell - you have to worry if they send in  Steven Segal

I would also argue that pilot sickness did not cause either of those accidents above. It may have been a contributing factor, but only as far as causing fatigued pilots to be more fatigued and make poor decisions. Even if neither pilot was sick, those accidents probably still would have happened. Plus they were sick before they got into the plane. They didn't get sick in flight.

All that said, any commercial pilot sitting in the driver's seat of an airplane should be prepared and capable of handling that aircraft themselves.

There's another link to that same story floating around here at a.se. It's from a military (Air Force, I believe) source, and Gongol comes across pretty low key in that one.

@Freeman I'm not trying to call Gongol out. What he did was brave. However even the AF media has engaged in a bit of sensationalism. I don't think he's claiming to be the savior that the articles try to make him out to be. I do take issue with some of his comments. He's quoted as saying the FO never taxied a 737. 100% untrue as that would have been in her FO training. And I still think it wasn't his place to "assess" her. What exactly would he have done if he found her lacking? She most likely WAS rattled. The most he realistically could have done is what he did: help reduce her workload. CRM.

do they fly in a pilot (like mid-air refuel)?

No, that isn't really feasible!
See answers to Can a passenger jet be towed to safety if it breaks down in midair?

do they leave it to the co-pilot to take care of such situations?

Yes. In both normal and emergency situations, the co-pilot is able to fly the aircraft, navigate to a nearby airport and land the aircraft without the assistance of the senior pilot.
From Skybrary

Here are some lines of defense:

The remaining pilot must assume or maintain control
Establish a safe flight profile and engage the autopilot; use all possible automation
Obtain cabin crew assistance
Inform ATC
If on an extended-range twin-engine operations (ETOPS)
  flight, the remaining pilot or PIC must assess whether to continue
  the flight, return to the departure airport or divert. The decision
  is based on:

Weather conditions at the destination or alternate
Reduction of flight time if diverting
Workload involved in single-pilot operation
Familiarity with the alternate
Condition of the incapacitated pilot
Availability of medical assistance
Overall safety of the flight

Arrange medical assistance upon arrival
Brief a cabin crew member to assist if required
Complete the approach and landing using the autopilot as much as possible
A partially incapacitated pilot should not be allowed to participate in the    subsequent operation of the aircraft, as
  judgment may be impaired
After landing, seek immediate medical assistance

See also IFALPA - Pilot Incapacitation

The remaining pilot must first assume command and maintain control of the aircraft. Furthermore the position of essential controls
  and switches should be checked, and in nearly all cases, use of the autopilot should be made and an emergency be declared.
  Use of the autopilot and priority of air traffic service are two obvious and effective ways of maintaining a tolerable level of workload.
The second step is to take care of the incapacitated flight crew member. The grounds for this are not entirely humanitarian; if left unattended an incapacitated pilot can become a major problem and in any case is a major distraction to the remaining crew. Thus
  the incapacitated pilot must be moved out of the range of flight controls. In all cases, the advisability of removing a pilot (perhaps unconscious) from the seat must be dictated by consideration of the phase of the flight, the crew available, and the contours of the
  flight deck.
Note: Consideration of the restraint and care of an incapacitated pilot dictates that cabin attendants are at least familiar with the
  operation of harness and seat controls
Finally, and after the incapacitated flight crew member has been taken care of, the remaining flight crew should re-organise the cockpit work and prepare for landing. Details will depend on many variables including such considerations as the type of aircraft being flown, phase of flight, en route and terminal weather, and many others.

How does commercial airlines prepare themselves for these kind of situations.

I imagine that it involves the usual measures

make pilots take regular medical tests.
make pilots responsible for reporting own or crew illness, fatigue etc.
prevent pilots eating the same meals in-flight.
write procedures for pilot incapacitation in-flight.
train flight crew to perform those procedures
review and revise the above based on experience of relevant events.

From what I've read, non-pilot flight-crew are often given very basic training so that they understand the basics of flight. For example Transport Canada requires flight attendants initial training to include a pilot-incapacitation drill, an understanding of aircraft parts including rudder, ailerons etc, principles of flight, etc etc.

Do they specifically check if there are any pilots in the passenger manifest

I believe the airline staff would often be aware of any airline pilots onboard (e.g. dead-heading crew) but not of GA or military pilots flying as normal passengers.

"In an emergency the co-pilot is able to fly the aircraft".. in all fairness, the co-pilot is able to do all of the above in non-emergency situations. In fact, in a normal airline, co-pilot flies about 50% of the time

@Radu094: That's a good point, answer updated accordingly. However in normal circumstances my understanding is the two pilots share the load, which helps during busy times like landing, performing checklists etc.

It's actually an airline specific rule that dictates whether or not pilots can eat the same meal, the FAA doesn't require it, so it can vary by airline.

Commercial operations do not normally do anything special to prepare for a pilot becoming sick. If a pilot has any kind of impairing health issue, then they are not supposed to fly at all. One of the purposes of the co-pilot is to be a backup for the pilot in case the pilot has a problem, like being incapacitated due to illness. In some cases small aircraft have crashed because they had only a single pilot who became incapacitated, but this does not happen to commercial flights because they invariably have two pilots on board. Even cargo flights have two pilots.
If both pilots were to become incapacitated, and the flight crew noticed, they would first have to get access to the flight deck and the purser has a code to do that. Then, in all likelihood, they would ask in the cabin if there were any pilots present. They do not know who might be a pilot or not, so they would have to ask. They will need to do this because to simply operate the radios requires knowledge and skill. For example, to talk you have to press a button. If you don't know where that button is located (there are hundreds of buttons in a cockpit), then you cannot talk, even if the radio is on the right frequency. RedGrittyBrick's idea that a steward would operate the aircraft or "help out" or that stewards are trained to operate an aircraft in an emergency is not correct.


text:
Determining Required Fuel from Payload/Range Diagram
I would like to determine the amount of fuel required for a flight at a given range/payload combination - ideally from the payload/range-diagram [1] of the corresponding aircraft alone.
I know that for the case of maximum payload, the fuel required for a flight at a given range can be read off the extended payload-range diagram as (cf. [2], Section 3.3):
$$m_{fuel}=m_1-m_2$$
where $m_2=MZFW$ and $m_1$ can be computed as $m_2=((m_1-m_2)/R(A))*R$

Image source: Figure 3.4 in [1]
But how can I read the fuel for an arbitrary payload that is smaller than the maximum payload (which is described in the diagram by the line up to point $A$)?
[1] Aircraft Fuel Consumption – Estimation and Visualization
[2] Aircraft Payload‐Range Analysis for Financiers

See here for the kind of payload-range diagram you need to find results for less than MTOW.

The gradient between points A and B of your diagram is determined by the overall efficiency of the airplane. It depends on the amount of fuel needed to fly a bit further by trading payload for fuel mass. Therefore, you will need to draw parallels to that line to the left and below it as shown in this diagram for a Boeing 777-200:

Boeing 777 range-payload diagram (picture source)
Note that the distance between lines for the same step reduction in take-off weight increases as you move leftward because the remaining fuel necessary to finish the flight needs to be carried over shorter distances.
To find the fuel mass for an arbitrary payload and a given range you need to draw a horizontal line at the right height of the OEW plus payload scale and then move rightward until you are above the desired range on the X-axis. The brake release gross weight for this payload-range combination can then be interpolated from the diagonal lines.
Of course, you can as well use the different corner points of the diagram and find the right values of the Breguet range equation and modfify those to arrive at the solution.


text:
How to fix JeppView VFR charts font display
Some of the VFR charts printed by JeppView for Windows incorrectly display various letters on the map. This is especially visible in the NDB/DME designations ("INN", "PAT", "RUM" all rendered incorrectly):

How can I make sure all the text in the chart is displayed correctly?

JeppView uses different proprietary fonts in its charts. If they are not embedded when the chart is saved to PDF, lettering will not display correctly.
On a Mac, running in the terminal
strings ~/Desktop/vfr_chart.pdf | grep FontName

returns the names of these fonts:
/FontName /FNTSBS+FT-7-Jeppesen-Proprietary-Y
/FontName /FNTSBS+FT-3-Jeppesen-Proprietary-U
/FontName /FNTSBS+FT-5-Jeppesen-Proprietary-W
/FontName /FNTSBS+FT-4-Jeppesen-Proprietary-V
/FontName /FNTSBS+FT-6-Jeppesen-Proprietary-X
/FontName /FNTSBS+FT-13-Jeppesen-Proprietary-C
/FontName /FNTSBS+FT-80-Jeppesen-Proprietary-N
/FontName /FNTSBS+FT-79-Jeppesen-Proprietary-M
/FontName /FNTSBS+FT-77-Jeppesen-Proprietary-Y-B
/FontName /FNTSBS+Arial-BoldMT
/FontName /FNTSBS+FT-11-Jeppesen-Proprietary-A
/FontName /FNTSBS+FT-1-Jeppesen-Proprietary-S
/FontName /FNTSBS+FT-3-Jeppesen-Proprietary-U

If these fonts are not installed on another computer, some lettering will not be rendered correctly, as your PDF viewer will attempt to use the next best fonts. I have not had any luck with manually installing these fonts on computers that do not have JeppView installed, so I instead recommend:
Always embed the fonts when exporting charts to PDF. The tool that comes with JeppView is NovaPDF. When printing (=exporting to PDF), toggle the option "PDF/A-1b" in the dialog window. The resulting PDF charts will display correctly on any device:


text:
Does a glider pilot with a PC canopy need to protect himself from UV radiation?
I and several of my glider pilot friends are developing skin cancers.  I am looking for information about the risk.  Canopy tints or polymer types that provide protection would be important to know.

Have you looked at appropriate types of skin cream/broad spectrum sun block's?

Most fabrics will only block UVB rays allowing the UVA rays through which penetrate deeper into the skin and cause more genetic damage. As far as color, it doesn't matter; if a fabric is capable of blocking UVA and UVB rays it will block the same amount regardless of the tint. The protection depends mostly on the type of material, density of the weave, and UV coatings. It's cheaper to buy something like Ray Bloc and apply to an already-owned canopy than to buy a brand new canopy. In any event, the highest rated fabric is UPF 50+ which means for every 50 UV rays, only 1 makes it through.

I assume that you mean polycarbonate by "PC". Polycarbonate plastics block nearly all UV radiation. Here is a typical transmission spectrum:

UV is the light below 400nm. As you can see, the curve shows 0% transmission in that range. In general, the risk of damage by radiation is greatly reduced by elimination of sub-400nm wavelengths.
Nevertheless, high energy visible light from 400-500nm should not be ignored and long exposure to such light can be damaging, especially to the eyes and is implicated in macular degeneration, and I know sailplane pilots with high hours who have suffered macular degeneration.
Also, if you are flying, you know that most pilots spend many hours out on the field waiting to launch or doing other chores, so there is plenty of time when you are not protected by a canopy at all.